Undo recent edits with u or revert all changes on the current line with U. Ctrl-r redoes what you just undid.
Commands you practise
Ctrl-r
Redo a change you just undid. It is the perfect antidote to an over-eager undo.
u
Undo your last change. Press u to instantly revert your most recent edit, easily recovering from accidental mistakes.
U
Revert all recent changes on the current line in a single keystroke. It is the ultimate panic button for a line you have over-edited.
Levels
Quick Slip (easy): Undo the accidental deletion of the first character in the print function.
Double Take (medium): Redo the bulk deletion of the temporary configuration line.
Line Restoration (hard): Revert all the scrambled deletions on this line in a single keystroke.
Each level opens a real Neovim session in your browser with a start file and a target file. Edit one into the other in as few keystrokes as you can, then race the vimbot's solution.